College of Horticulture, Xinjiang Agricultural University, Xinjiang, Urumqi, China.
Xinjiang Uygur Autonomous Region Grapevine and Melon Fruit Research Institute, Xinjiang, Shanshan, China.
PeerJ. 2024 Jul 25;12:e17654. doi: 10.7717/peerj.17654. eCollection 2024.
The objective of this study was to explore the fungistatic mechanism of fig leaf extract against and to provide a theoretical basis for the development of new plant-derived fungicides.
The fungistaticity of fig leaf extract were analyzed by the ring of inhibition method. was selected as the target for analyzing its fungistatic mechanism in terms of mycelial morphology, ultrastructure, cell membrane permeability, membrane plasma peroxidation, reactive oxygen species (ROS) content and changes in the activity of protective enzymes. The effect of this extract was verified in melon, and its components were determined by metabolite analysis using ultraperformance liquid chromatography‒mass spectrometry (UPLC‒MS).
Fig leaf extract had an obvious inhibitory effect on , and the difference was significant ( < 0.05) or highly significant ( < 0.01). Scanning and transmission electron microscopy revealed that hyphae exhibited obvious folding, twisting and puckering phenomena, resulting in an increase in the cytoplasmic leakage of spores, interstitial plasma, and the concentration of the nucleus, which seriously damaged the integrity of the fungal cell membrane. This phenomenon was confirmed by propidium iodide (PI) and fluorescein diacetate (FAD) staining, cell membrane permeability and malondialdehyde (MDA) content. Fig leaf extract also induced the mycelium to produce excessive HO,which led to lipid peroxidation of the cell membrane, promoted the accumulation of MDA, accelerated protein hydrolysis, induced an increase in antioxidant enzyme activity, and disrupted the balance of ROS metabolism; these findings showed that fungal growth was inhibited, which was verified in melons. A total of 1,540 secondary metabolites were detected by broad-targeted metabolomics, among which the fungistatic active substances flavonoids (15.45%), phenolic acids (15%), and alkaloids (10.71%) accounted for a high percentage and the highest relative content of these substances 1,3,7,8-tetrahydroxy-2- prenylxanthone, 8-hydroxyquinoline and Azelaic acid were analysed for their antimicrobial, anti-inflammatory, antioxidant, preventive effects against plant diseases and acquisition of resistance by plants. This confirms the reason for the fungicidal properties of fig leaf extracts.
Fig leaf extract has the potential to be developed into a plant-derived fungicide as a new means of postharvest pathogen prevention and control in melon.
本研究的目的是探讨无花果汁提取物对 的抑菌机制，并为开发新型植物源杀菌剂提供理论依据。
采用抑菌圈法分析无花果汁提取物的抑菌活性。选择 作为目标，从菌丝形态、超微结构、细胞膜通透性、膜质过氧化、活性氧（ROS）含量和保护酶活性变化等方面分析其抑菌机制。在甜瓜上验证该提取物的效果，并采用超高效液相色谱-质谱联用（UPLC-MS）进行代谢物分析确定其成分。
无花果汁提取物对 有明显的抑制作用，差异显著（ < 0.05）或极显著（ < 0.01）。扫描和透射电子显微镜显示， 菌丝体出现明显的折叠、扭曲和起皱现象，导致孢子、间质血浆和核的细胞质渗漏增加，严重破坏了真菌细胞膜的完整性。碘化丙啶（PI）和荧光素二乙酸（FAD）染色、细胞膜通透性和丙二醛（MDA）含量证实了这一现象。无花果汁提取物还诱导菌丝产生过量的 HO，导致细胞膜脂质过氧化，促进 MDA 积累，加速蛋白质水解，诱导抗氧化酶活性增加，破坏 ROS 代谢平衡；这些发现表明，真菌生长受到抑制，在甜瓜上得到验证。通过广泛靶向代谢组学检测到 1540 种次生代谢物，其中黄酮类（15.45%）、酚酸类（15%）和生物碱类（10.71%）等抑菌活性物质含量较高，相对含量最高的物质为 1,3,7,8-四羟基-2- 丙烯基黄烷酮、8-羟基喹啉和壬二酸，分析其抗菌、抗炎、抗氧化、预防植物病害和植物获得抗性的作用。这证实了无花果汁提取物杀菌特性的原因。
无花果汁提取物具有开发为植物源杀菌剂的潜力，可作为甜瓜采后防治病原菌的新手段。
